The results show that IFN-γexpression exists in cytomembrane of granulated cells in late tertiary follicle during dioestrus,granulated cells late tertiary follicle and mature follicle during oestrum, ovarian follicle during trimester of pregnancy, granulosa lutein cell in the 7th week of pregnancy, nucleus of theca lutein cell in the 12th, 16th, 20th week of pregnancy.

A strain of hog Cholera virus has been adapted and maintained 430 passages in rabbits over past four more years. This virus strain readily multiplied in rabbits and it caused high and relatively durable hyperthermia. A series of experiments were performed on pigs in both laboratory and field trials and it was proved that the vilulence of the virus has been gradually and markedly attenuated to pigs after lapinized through rabbits. Before early 90 passages it caused mortality to both weaned and suckling piglets....

A strain of hog Cholera virus has been adapted and maintained 430 passages in rabbits over past four more years. This virus strain readily multiplied in rabbits and it caused high and relatively durable hyperthermia. A series of experiments were performed on pigs in both laboratory and field trials and it was proved that the vilulence of the virus has been gradually and markedly attenuated to pigs after lapinized through rabbits. Before early 90 passages it caused mortality to both weaned and suckling piglets. Thereafter, pigs from 62 herds were vaccinated With viruses from 91 to 165 rabbits passages only developed less reactions and mortality indicating further attenuation. But some of those suckling piglets of unthrifty condition died from enteritis complications following post-vaccination reactions, The Virus has been proved to be markedly attenuated after 156 more rabbits passages by the facts when pigs of different ages including 10 to 40 days suckling piglets vaccinated with the virus of the 214th and later passages without showed any subclinical reaction and there were no bad effects to their growth. During 1957, the virus after 300th passages was used as seed in preparing vaccines in many provinces, a total of 6752601 pigs of different ages and weights were vaccinated. The multiplication of the virus in pigs is occassionally accompanied by slight febrility. Generally no clinical reactions could be observed and slight loss of appetite was exhibited only by animals in poor condition of health. No post-vaccination losses occurred, although large doses of the virus were given. Further safety tests of the vaccine were performed and proved that the attenuation of the virus was quite reliable and safe. 15 days suckling piglets were perfectly healthy after inoculated with the virus which had been turned back to susceptible pigs for 6 serial passages and this indicated the stability of virulence of the lapinized vaccine for pigs. The vaccinated animals excreted no virus from urine or keep infective virus within the body for long intervel. Unvaccinated animals were kept with vaccinateb ones for 60 days. Every unvaccinated contact proved susceptible to challenge with virulent virus, performed 2 months after vacination. In our experiments the vaccination proved entirety safe for suckling pigs, which also developed relatively high degree of immunity. In several state farms a total of 191 sows in different stages of pregnancy were vaccinated. The animals exhibited no side reaction whatever and delivered normal fetouses. According to our results the attenuated rabbits virus has been considered to be an ideal live vaccine for hog cholera control, so that it has been used for mass vaccination within the whole country since 1957. More than 300 millions of vaccine doses have been inoculated in the field, and the results were reported to be quite safe and satisfactory. Since 1956, this Chinese or “K” strain of lapinized HC virus was introduced into USSR, Hungary, Bulgaria. DPRK, Romania, Vitnan and then other countries. The results of comparative experiments and successful mass vaccination in the field over many years in different countries have comfirmed that this C_strain of HC vaccine is very safe and has excellent immunogenicity. This live virus vaccine was considered an excellent tool in preparing the ground for the complete eradicaton of HC, such as new achieved in DPRK, Hungary, Bulgaria and some other European countries.

Embryos were obtained from dairy cows after superovulation which was induced by intramuscular injection of FSH with a total dosage of 500—600 RU per cow commencing on day 15 or 16,with a daily dosage of 100—150 RU in two injections within 4—5 consecutive days. With the aid of a two-way catheter inserted into the cervix ute- ri,embryos were recovered on day 6,7 or 8 after artificial insemi- nation.In 1978,17 out of the 26 donors (65%) delivered 38 ova,33 were fertilized eggs.This gave a recovery rate of 1.3 embryos...

Embryos were obtained from dairy cows after superovulation which was induced by intramuscular injection of FSH with a total dosage of 500—600 RU per cow commencing on day 15 or 16,with a daily dosage of 100—150 RU in two injections within 4—5 consecutive days. With the aid of a two-way catheter inserted into the cervix ute- ri,embryos were recovered on day 6,7 or 8 after artificial insemi- nation.In 1978,17 out of the 26 donors (65%) delivered 38 ova,33 were fertilized eggs.This gave a recovery rate of 1.3 embryos per donor.In 1979,83 embryos and 3 unfertilized ova were collected from 21 donors,among them 3 did not bear any ovum. For embryo transfer,an insemination catheter was introduced into the cervix uteri of the recipient and eggs with medium were poured in.In 1978,20 embryos were transferred to 18 recipients.4 recipien- ts were pregnant,3 of them had born 4 calves,and the other one aborted on the third month of pregnancy.The pregnancy rate and the embryo survival rate were 22% and 20% respectively.

SUMMARY In bactrian camel the average gestation period counted from the day of ovulation is 2102,2+11.53 (with a range of 374—419) days. The corpus luteum verum averages 2.6(1.8—3.5) cm in diameter (or long axis), i.e.much larger than the corpus luteum spurium. Almost all of the fetuses are located in the left horn. Pregnancy diagnosis by rectal examination is described in detail.